Heatmaster MF Series Operation And Maintenance Manual page 20

Description
The Ranco electronic temperature control (ETC) is
designed to provide on/off control for heating and
cooling. It is equipped with a liquid crystal display
(LCD) that provides a constant readout of the sensed
temperature, and a touch keypad that allows the user to
easily and accurately select the set point temperature,
differential and heating/cooling mode of operation.
Programming steps and Display
The ETC can be programmed in four simple steps using
the LCD display and three keys on the face of the control.
STEP 1 To start programming press the SET key once
to access the Fahrenheit/Celsius mode. The
Display will show the current status, either F for
degrees Fahrenheit or C for degrees Celsius. Then
press either the up or down arrow key to toggle
between the F or C designation.
STEP 2 Press the SET key again to access the set point.
The LCD will display the current setpoint and
the S1 indicator will be blinking on and off to
indicate that the control is in the set point mode.
Then press either the up key to increase or the
down key to decrease the setpoint to the desired
temperature.
STEP 3 Press the SET key again to access the differential.
The LCD will display the current differential and
the DIF1 indicator will be blinking on and off to
indicate that the control is in the differential mode.
Then press the up key to increase or the down key
to decrease the differential to the desired setting.
STEP 4 Press the SET key again to access the cooling or
heating mode. The LCD will display the current
mode, either C1 for cooling or H1 for heating.
Then press either the up or down key to toggle
between the C1 or H1 designation. (This setting
must remain at H1 for proper furnace operation
once more and programming is complete.
NOTE: The ETC will automatically end programming if no
keys are pressed for thirty seconds. Any settings that have
been changed on the control will be stored at that point.
Step
1
2
3
4
Troubleshooting Error Messages
Display Message
E1
E2
EP
EE
CL
Input Voltage:
Temperature Range: 30°F to 220°F
Press the SET key
Differential Range:
Sensor:
Power Consumption: 120/208/240 VAC: 100 Milliamps 24
Indicator Description
F or C Fahrenheit or Celsius Scale
S1 blinking Setpoint Temperature
DIF1 blinking Differential Temperature
C1/H1 Cooling or Heating Mode
Appears when either the up or down key is pressed
when not in the programming mode.
To correct: If the E1 message appears even when no
keys are being pressed replace the control.
Appears if the control settings are not properly
stored in memory.
To correct: Re-set all settings. If the display continues
to show E2, replace the control.
Appears when the probe is open, shorted, or
sensing a temperature that is out of range
To correct: Check to see if the sensed temperature
is out of range. If not, check for probe damage
by comparing it to a known ambient temperature
between –30°F and 220°F. Replace the control if
necessary.
Appears if the EEPROM data has been corrupted.
To correct:
Replace the control.
Appears if calibration mode has been entered.
To correct: Remove power to the control for at least
appears, replace the control
120 or 208/240 VAC (24 VAC
optional), 50/60 Hz
1°F to 30°
Thermistor, 1.94 in. Long x .025 in.
Dia. with 8 ft. cable
VAC: 2-6 VA